An attempt to get testimony from one of George Zimmerman's former college professors via Skype was interrupted Wednesday after other users of the video chat service caught on and called prosecutor Rich Mantei's username in the middle of court.

Scott Pleasants, a Seminole State College professor who said Zimmerman had taken his online criminal justice class, testified via Skype from Colorado.

But as Pleasants' testimony was broadcast live on television, dozens of other Skype users inundated Mantei with Skype calls.

Follow LIVE UPDATES from Day 18 of the trial.

State will have to wait to rest case

Prosecutors were hoping to rest their case Wednesday, but Florida Department of Law Enforcement DNA expert Anthony Gorgone's testimony lasted for more than three hours, in part because of a long cross-examination by defense attorney Don West.

Judge Debra Nelson said she would not bring in the jury during the July 4th holiday on Thursday. The jurors were dismissed until Friday morning.

Wednesday's testimony

  • Anthony Gorgone, an FDLE crime lab DNA analyst.
  • Amy Siewert, an FDLE crime lab analyst who examined Zimmerman's gun.
  • Scott Pleasants, a criminal justice professor at Seminole State College; testified via Skype, and then on the phone.
  • Jim Krzenski, a Sanford Police administrator who testified on Zimemrman's ride-along application.
  • Capt. Alexis Carter, a U.S. Army captain who taught Zimmerman's criminal justice course.
  • Lt. Scott Kearns, with the Prince William County, Va. Police Department.
  • Sonja Boles-Melvin, a registrar at Seminole State College.

Anthony Gorgone is a DNA expert for the Florida Department of Law Enforcement.

Gorgone said tests of George Zimmerman's gun revealed his DNA on the firearm's grip, but not Trayvon Martin's.

He also testified that Zimmerman's DNA was not found under the unarmed teen's fingernails, but it was found among blood on a shirt Martin was wearing under his hooded sweatshirt.

Zimmerman has said he shot the 17-year-old in the chest to protect himself as Martin reached for his firearm during a fight.

While cross-examining Gorgone, defense attorney Don West focused on the packaging of the DNA samples, suggesting they could have led to the samples being degraded. Gorgone told him that Martin's two sweatshirts had been packaged in plastic while wet, instead of a paper bag where they can dry out, and when he opened the samples they smelled of ammonia and mold.

Prosecutors called the DNA expert to the witness stand to refute Zimmerman's contention that he fatally shot Martin in self-defense. Zimmerman has said Martin was reaching for his firearm during a fight when he fired the gun into Martin's chest.

Defense tries to question Crump again.

George Zimmerman's lawyers asked again for a delay in proceeding with the trial Wednesday afternoon so they could take a deposition of Benjamin Crump, the attorney representing Trayvon Martin's family.

Judge Nelson scolded the defense for asking again, saying they have had a month to do it, and she did not want the jury to lose another day of their lives to sequestration without this trial moving forward.

Amy Siewert is a crime lab analyst for the Florida Department of Law Enforcement.

Prosecutors began a detailed questioning on the forensics analysis performed on Zimmerman's gun after calling Siewert to the witness stand.

Siewert testified that residue and tearing on Martin's sweatshirt showed Zimmerman's gun was touching Martin's chest when it fired.

She also demonstrated for jurors how the gun is fired by holding the 9 mm semi-automatic handgun, and under cross-examination, said the gun was safe to carry around loaded because it won't fire unless the trigger is pulled.

Scott Pleasants is a Seminole State professor who taught an online criminal justice class taken by Zimmerman.

Pleasants, who was in Colorado on Wednesday, called in via Skype to testify. But as it was broadcast live on television, prosecutor Rich Mantei's username appeared on the screen, prompting multiple Skype users to inundate Mantei with Skype calls, interrupting Pleasants' testimony.

A Skype user named 'salman talpur' was among several who tried to call Mantei multiple times in the middle of court. That was followed by a bombardment of other requests.

Judge Debra Nelson finally ordered the state to call Pleasants back on a cell phone. Defense attorney Mark O'Mara finished questioning Pleasants over the phone.

Jim Krzenski is an administrator with the Sanford Police Department.

Krzenski testified about an application Zimmerman submitted to ride around with Sanford Police in 2010.

According to Krzenski's testimony, Zimmerman wrote that he was seeking to "solidify his chances" of becoming a law enforcement officer.

U.S. Army Capt. Alexis Carter is a military attorney who taught George Zimmerman's criminal justice class.

Carter testified that the class Zimmerman took did cover Florida's "stand your ground" law, which says a person has no duty to retreat and can invoke self-defense in killing someone if it is necessary to prevent death or great bodily harm.

Carter described Zimmerman as one of his better students and got an "A" in his class. He even asked the defendant, "How are you doing, George?" when asked to identify Zimmerman.

Zimmerman had maintained in an interview with Fox News last year that he did not know about the law. Prosecutors showed the jury that videotaped interview on Tuesday, and then called Carter to testify on Wednesday that the law was covered in his class.

Under cross-examination, Carter gave two definitions of legal concepts that seemed to bolster the defense's case. He explained that a person can make a self-defense argument if the person has a "reasonable apprehension" of death or great bodily harm.

"It's imminent fear. The fact alone that there isn't an injury doesn't necessarily mean that the person didn't have a reasonable apprehension or fear," Carter said. "The fact that there are injuries might support there was reasonable apprehension and fear."

Carter also explained the concept of "imperfect self-defense," when a person is being threatened but then counters with a force disproportionately greater than the force used against them.

"They would have the right to defend themselves?" said defense attorney Don West.

"Right," Carter said.

Scott Kearns is a lieutenant with the police department in Prince William County, Virginia.

Lt. Kearns testified that George Zimmerman applied to his police agency in 2009.

He said Zimmerman wasn't initially hired because of a less-than-stellar credit history.

Sonja Boles-Melvin is a registrar at Seminole State College.

Boles-Melvin's testimony was the quickest so far in the trial, confirming that George Zimmerman was enrolled in criminal justice courses at Seminole State.

Zimmerman's school records allowed

Judge Debra Nelson ruled Wednesday morning, before the jury entered the courtroom, that prosecutors could present Zimmerman's school records to the jury to show he knew about Florida's self-defense law and had aspirations of becoming a police officer.

Prosecutors said Zimmerman's ability to understand criminal investigations and desire to be a police officer doesn't show wrongdoing, but is relevant to Zimmerman's state of mind on the night Martin was killed.

"He has applied to be a police officer before, he still wants to be one, according to some of his homework assignments...this wasn't some sort of passive thing," said prosecutor Rich Mantei, who noted Zimmerman took a course on how to be a good witness and expressed a desire to go on police ride-alongs. "This is simply a fact the jury ought to know."

When he was interviewed by detectives, Zimmerman spoke "in written police jargon" and talks about "justifiable use of force" and says he "unholstered my firearm, not I pulled my gun," Mantei said.

The defense believes the items are irrelevant and asked the judge not to allow them.

Defense attorney Mark O'Mara said Tuesday that if prosecutors start bringing up Zimmerman's past, the defense will dig into Martin's past, including fights. The judge had ruled previously that Martin's past fights, drug use and school records couldn't be mentioned in opening statements.

"There is no relevance and the suggested relevance will be far more outweighed by the prejudice," O'Mara said of the evidence admitted Wednesday.